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GEORGE B. GARLINGHOUSE, OF NORTH MADISON, INDIANA.

Letters Patent No. 64,757, dated ZiIay 14, 1867. i

IMPROVEMENT IN KNUGKLE-JOINT'.

TO WHOM IT MAY CONCERN:

Be it known that I, GEORGE B. GRLINGHOUSE, of North Madison, Jefferson eounty,.Indiana, have invented a new and. useful Improvement. in Knuckle-Joints; and .I do hereby declare the following to be' a full, clear, and exact description thereof, reference being had to the accompanying drawings, making part of this specification.

This is an improvement in the class ot' mechanical devices known as kn`ee," toggle, or knuckle joints, and is intended to combine strength, precision, and mobility in a greater degree than has heretofore been obtained.

Figure 1 is a perspective view of a `joint embodying my improvement.

Figure 2 is a side elevation of the same.

The two limbs or arms A A instead of being halved into each other and united by a single pin about which they revolve in common, as in theordinary hinge or rule joint, are provided with cylindrical terminations B B', which in every position of the'joint are held in juxtaposition by links-C C secured toisaid limbs` by pivot-bolts D D applied at the precise centres of respective cylinders. In order to prevent any slipping ofthe cylindricalterminations one upon the other, and to hold the two always and with precision to the same relative position with respect to each other, I provide on each limb one or more series of cogs or segmental racks E E', whose pitch line is coincident with the cylindrical termination of its limb, and meshes with a corresponding rack or racks on the opposing one. The strain on such a joint being wholly one of thrust, it will be seen that the duty of the links and cogs is confined to holding the two limbs in place, and thatthe entire stress of the toggle falls upon the solid and accurately cylindrical terminations of' the limbs, instead ot' upon the connecting pin as heretofore, and the motion being a purely rolling one, the resistance due to friction is practically eliminated, thus greatly increasing the power, accuracy, mobility, and general vefficiency oi' this valuable class of mechanical movements. Although selecting for illustration the preferred type or form of my invention, the right is reserved of modifying the same as vcircumstances may suggest; for example, the pivot-bolts and links may be replaced by bosses upon the limbs, concentric with their cylindrical terminations, connected by enclosing yokes or bridles, while the two pairs of racks may be replaced by a single pair situated at or near theY mid width of' the limbs; or, the said terminations may be held in place by two or more ilexible straps crossing each other at the lineof intersection, and attached by their extremities to theopposing limbs.

I claim herein as new, and of my inventionl i A knuckle-joint, provided with cylindrical terminations adapted to roll upon each other, and held in place by racks and links, or their equivalents, substantially as set forth.

v Intestimony of which invention I hereunto set my hand.

l GEORGE B. GARLINGHO'USE.

Witnesses:

GEO. H. KNLGHT, JAMES H. LAYMAN. 

